Process of shaping tubing



April 17, 1956 e. E. BERINGER PROCESS OF SHAPING TUBING 4 Sheets-Sheet 1 Filed Sept. 8, 1953 IN V EN TOR.

April 17, 1956 e. E. BERINGER PROCESS OF SHAPING TUBING 4 Sheets-Sheet 2 Filed Sept. 8, 1953 INVENTOR. 650/265 5 BEE/W688 ATTORNEY April 7, 1956 5. E. BERINGER PROCESS OF SHAPING TUBING Filed Sept. 8, 1953 4 Sheets-Sheet 3 1 N V EN TOR. 650%.; 5 Baa/v05? ATTORNEY April 7, 1956 e. E. BERINGER PROCESS OF SHAPING TUBING 4 Sheets-Sheet 4 Filed Sept. 8, 1953 I N V EN TOR. 95mm 5 BEE/N65? United States Patent '0 PROCESS OF SHAPING TUBING George E. Beringer, South Bend, Ind., assignor to Bendix Aviation Corporation, South Bend, Ind, a corporation of Delaware Application September 8, 1953, Serial No. 378,875

2 Claims. (Cl. 29-538) The present invention is directed to a method of shaping metallic stock of essentially tubular form and the final product resulting from the method of my invention may constitute a hollow cylinder member used in a landing gear shock strut or as a tail bumper of an airplane.

More specifically my invention is directed to a method of imparting the desired exterior and interior contour, particularly the latter, to a hollow member such as the aforementioned cylinder. The desired interior contour of the cylinder is usually obtained by a so-called bottle boring process, however,with my invention this contour is efiected by a more effective and much simpler process. It is common practice in the shaping of tubular stock to obtain the desired interior contour by this bottle boring operation; however such an operation is difficult and expensive. By the use of my invention the metal, whether it be annealed aluminum, steel or other material, is pressed inwardly by an intrusion of the metal to obtain the interiordiameter desired; the cost of production is lowered and the desired internal contour of the work is effected in a minimum of time.

-Yet another object of my invention is to provide a method of configuring a section of a tube, said method including, together with other steps, the step of applying a deformative pressure to a section of the tube by a tool, such as a two part die, shaped and positioned to displace parts of the tube section inwardly to provide the desired contour of the interior wall of said section and provide the desired grain flow of the material displaced.

The principal object of my invention is to provide a method of shaping metallic stock of tubular shape and suitable hardness whereby the O. D. of the stock is first configured as desired, the stock so configured being then forced through a die to displace the configured material to eifect the desired I. D. configuration of the stock.

The foregoing and other objects and advantages will become apparent in view of the following description of a preferred embodiment of my invention taken in conjunction with the drawings, wherein:

Figure 1 is a front view, partly in section, of the press and die holding fixture for effecting the principal step of my invention;

Figure 2 is a sectional view disclosing the original stock of tube material to be worked on by the several steps constituting my invention;

Figure 3 is a sectional view of the stock of Figure 2 after being formed by the first step of my invention;

Figure 4 is a sectional view of that part of the stock of Figure 3 which is subjected to the principal step of my invention that is the forming operation to decrease the interior diameter of a portion of the stock;

Figure 5 is a sectional view disclosing the stock of Figure 4 after being exteriorly machined and threaded;

Figure 6 is a sectional view disclosing the press and fixture of Figure 1, with the hollow cylinder or tube of Figure 3, being positioned in the fixture just prior to the forming operation of shaping the upper end portion of .said cylinder;

2,741,833 Patented Apt? 17, 1

Tee

Figures 7 and 8 are sectional views disclosing the shape taken by the cylinder of Figure 3 as the ram operates to force the cylinder through the die, the final shape of the upper end portion of the cylinder being that disclosed in Figure 4;

Figure 9 is a sectional view, similar to Figure 3, disclosing another specimen of work and after the stock has been exteriorly machined preparatory to the step of shaping the work by the die pressing operation; and

Figure 10 is a sectional view of that part of the work of Figure 9 which is subjected to the pressing operation, this view disclosing the shape of the work after said operation.

There is disclosed in Figure 1 a forming die mounted in a press for shaping the hollowvcylinder or tube of my invention the operation performed by this press and fixture combination being the principal step of my invention. In describing this device, reference will also be made to Figures 6, 7 and 8 inasmuch as the device is, in these figures, shown in greater detail.

The fixture of Figures 1, 6, 7 and 8 preferably includes a tubular shaped die holder or fixture 10 mounted upon a footing or pedestal 12. A die 14, tubular in shape and having an end flange 15 seated upon the die holder, is telescoped within the upper end of said holder. This die is, for the particular workdisclosed in the drawings, split to accommodate said work that is a hollow cylinder 16 which is to be shaped. This cylinder, which may be the inner cylinder of a landing gear shock strut used on an airplane, may be provided with an end member 18, Figure 6, shaped as desired- At this juncture it is to be noted that the work to be shaped may be used in many arts, for example, a tube or cylinder produced by the process of my invention may constitute a part of the mechanism of an' automotive vehicle.

The cylinder 16 in its original state is disclosed in Figure 2 the tubular portion thereof constituting the major part and being uniform or substantially uniform in cross section.

The first step of my invention is to configure the O. D. of the stock to a desired size and shape and in the illustration of Figure 2 the outer surface of the stock is machined to the shape disclosed in Figure 3 there being provided, by this operation, a thickened end portion 20 said portion being of uniform thickness throughout its length save for a tapered end portion and preferably joined to the relatively thin main body portion of the cylinder by a tapered portion 22. The work, that is the cylinder 16 of Figure 3, is then positioned in the fixture as disclosed in Figure 6 with the two like and mating parts of the die 14 surrounding the cylinder. in this position, it will be noted that the tapered portion 22, Figure 3, nests Within a tapered portion 24 of the die.

The next step in processing the work to its final shape is to force the work, preferably in a cold state, through the die; and this is effected by a ram 26 acting upon the thickened end 20 of the cylinder, all as disclosed in Figures 7 and 8 of the drawings. In this operation the ram is guided by a movable sleeve 28 which moves with and guides the ram until the sleeve movement is arrested by the tapered section of the die. I prefer to force the work through the die by the compression load of the ram; however, with but slight change in the construction of the press and fixture combination the work may be pulled through the die or forced by a combination of pushing and pulling as desired. As is disclosed in Figure 7, the work is, in this operation, thickened inwardly at its upper end, that is the open end; and in its final shape, as is disclosed in Figures 4 and 8, the stock has been pressed inwardly. The interior diameter of the thickened section 20 has, by this operation, been decreased to the desired shape and the exterior diameter of said section has been decreased down to that of the {throughout the major .portion thereof.

. amines V formerly the end portion 20, is threaded to receive a nut or othenmember .dependingupon .themechanism or unit ofnvhich the .workis to become apart.

.IThere is disclosed inFiguresS and 10 another specimen of work made in=accordancewithrny invention. Figure 9..discloses the.state' of the work after the toriginalostock has .been exteriorly machined. .The part 29 tobe die pressed. has :a progressively thickened tapered portion -36 which merges into another tapered portion 32; and the latterportion merges intoathickenedportion 34 of univforrnlthickness .save for a relatively short tapered .end

portion 36. ..T.he Work is then placed in the forming fixture, Ihfizdlfi, :prcferably.split,..beingsuitably shaped for the. -.par.ticular .work; .and after the pressing process. is effected there results the product disclosed in full lines in Figure 10. As will be notedfromthelatter figure the .metal is pressed inwardly to theinternalcontour disclosed,

the outer diameter of the. .work being then uniform Then after the work :is .heattreated theexterior surface is machined as desiredfthe finalproduct being disclosed in dotted lines in Figure 10. There isthus vprovidecL'by the several: steps of my-invention, a method of shapinga metallic. tube or hollowicylinder totprovide a part of a machine or unit such as an. airplane landinggear shock-strut.

' Although aparticular embodimentof my invention has been ldescribed,.it will beunderstood by those-skilled in lthe art that the object of the invention may be attained by the .use of constructions difierent in certain respects from .thatdisclosed without departing from the underlying principles of the invention. I therefore desire by the following claims to :include Within the scope of my invention all such variations .andmodifications by, which substanlt'ially the results of my invention may be obtained through the use of substantially the same or equivalent means.

I claim:

I. The method'of configuring ah'ollow' cylinder member adapted to be used in a; tail bumper assembly of an airplane, comprising first so machining the exterior surface of the cylinder member as to provide a relatively thick end portion of substantially uniform thickness throughout its length, said end-portion being joined to the main body portion.ofithe cylinder-by altapered portion, then 'cold pressing by forcing said end portion through a die which is-.shaped toconfornrto the external shape of the thickened end portion, said operationpressing said end portion inwardly thereby changing both-the in r r c n our and. e teri r contourthe f. nd-su quently machining the exterior surface of said cold pressed end portion of the cylinder member to effect the desired contour thereof, and lastly threading a portion of said cold pressed portion.

2- Themct dntcnnngm n .hol pw.' y in er member adap d tov ei s din ata tb mn nassemb y f an ai pl compri ing rstsamachmii theeirte hnsfle' f at th cy inderm mb rv sztclp mvi e a rela ivel thick endrpiortion ow throughout its. length, said. endpq ti n be n -join d tot mainbo yport n. of th cy i e y a. tapered. p rt n. then c ld n essinglbv fuming said end p ti n thiq a die which is $11,815 ed to c nform vto .theex e na ll api of the thickened end ,p0r t ion,',said operation pr, sihgisaid e porti n nw rd y her byc anging.bothflthemteri r cont ur andexteriorqcnnt n the e f, a d subsequently machining the extet orsurfa e. f saidc I pr ssed e portion of thecylinder .membe'rto effect :the desired contour thereof.

References Cited in the file ofpatent UNITED STA ES PATENTS nesasss Cross Jan.72-2, ;1- 929 'l;984,75l -McBride -;-De'c.-13,--1934 1,987,718 Smith r -Jsn.-15,-123$ 2 ,026,133 'Mapes Dec. 31,1935

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